Two-Higgs-Doublet Models with CP violation

TL;DR

This paper explores the parameter space of Two-Higgs-Doublet Models with CP violation, focusing on small soft mixing terms, and discusses scenarios where Higgs bosons are heavy or appear SM-like at colliders.

Contribution

It identifies conditions for naturally small CP violation and FCNC effects in Two-Higgs-Doublet Models, including non-decoupling SM-like scenarios with light Higgs bosons.

Findings

Small m_{12}^2 leads to suppressed CP violation and FCNC effects.

Heavy Higgs bosons can have masses around 1 TeV.

SM-like Higgs scenario can occur without decoupling, with small bc^2.

Abstract

We consider the Two-Higgs-Doublet Model and determine the range of parameters for which CP violation and Flavor Changing Neutral Current effects are naturally small. It corresponds to small values of the mass parameter m_{12}^2, describing soft (\phi_1,\phi_2) mixing in the potential. We discuss how, in this approach, some Higgs bosons can be heavy, with mass of the order of 1 TeV. The possibility that at the Tevatron, LHC and an e^+e^- Linear Collider, only one Higgs boson will be found, with properties indistinguishable from those in the Standard Model (SM), we define as the SM-like scenario. While this scenario can be obtained with large \mu^2 \sim \Re m_{12}^2 parameter, in which case there is decoupling, we here discuss the opposite case of small \mu^2, without decoupling.